Table I. Summary of tomato UBC domain-containing proteins, their nomenclature, classification, activity as ubiquitin E2 enzymes, and specificity toward immunity-associated E3 ubiquitin ligases in an in vitro ubiquitination assay.

nd, This protein was not tested for the assay.

Chromosome Locus	Gene Name	Group No.	Protein in E. coli	E2 Activity	E2/E3 Specificity for AvrPtoB
Solyc06g072570.2.1	UBC27	I	Yes	Yes	No
Solyc06g070980.2.1	UBC1	II	Yes	Yes	No
Solyc03g113100.2.1	UBC2	II	Yes	Yes	No
Solyc02g067420.2.1	UBC3	II	Yes	Yes	No
Solyc02g087750.2.1	UBC41	II	Yes	Yes	No
Solyc12g056100.1.1	UBC8	III	Yes	Yes	Yes
Solyc08g008220.2.1	UBC9	III	Yes	Yes	Yes
Solyc05g050230.2.1	UBC10	III	Yes	Yes	Yes
Solyc03g033410.2.1	UBC11	III	Yes	Yes	Yes
Solyc07g066080.2.1	UBC12	III	Yes	Yes	Yes
Solyc10g011740.2.1	UBC28	III	Yes	Yes	Yes
Solyc02g083570.2.1	UBC29	III	Yes	Yes	Yes
Solyc03g007470.2.1	UBC30	III	Yes	Yes	Yes
Solyc01g095490.2.1	UBC31	III	Yes	Yes	Yes
Solyc08g081950.2.1	UBC38	III	Yes	Yes	Yes
Solyc06g082600.2.1	UBC39	III	Yes	Yes	Yes
Solyc06g007510.2.1	UBC40	III	Yes	Yes	Yes
Solyc12g099310.1.1	UBC32	IV	Yes	Yes	No
Solyc03g123660.2.1	UBC33	IV	Yes	Yes	No
Solyc06g063100.2.1	UBC34	IV	Yes	Yes	No
Solyc05g054550.2.1	UBC7	V	Yes	Yes	No
Solyc04g011430.2.1	UBC14	V	Yes	Yes	No
Solyc05g054540.2.1	UBC35	V	Yes	Yes	No
Solyc09g009720.1.1	UBC36	V	Yes	Yes	No
Solyc10g012240.2.1	UBC4	VI	Yes	Yes	No
Solyc01g094810.2.1	UBC5	VI	Yes	Yes	No
Solyc08g081270.2.1	UBC6	VI	Yes	Yes	No
Solyc11g071870.1.1	UBC15	VI	Yes	Yes	No
Solyc11g071260.1.1	UBC21a	VII	Yes	nd	nd
Solyc11g065190.1.1	UBC20	VIII	Yes	Yes	No
Solyc07g062570.2.1	UBC13	IX	Yes	Yes	No
Solyc10g007260.2.1	UBC13-2	IX	Yes	Yes	No
Solyc04g080810.2.1	UBC16	X	Yes	Yes	No
Solyc02g084760.2.1	UBC17	X	Yes	Yes	No
Solyc01g111680.2.1	UBC23a	XI	Yes	nd	nd
Solyc02g078210.2.1	UBC24a	XI	Yes	nd	nd
Solyc10g007000.2.1	UBC25a	XI	Yes	nd	nd
Solyc01g079290.1.1	UBC26a	XI	Yes	nd	nd
Solyc10g081160.1.1	UBC22	XII	Yes	Yes	No
Solyc07g024070.1.1	UBC37	XIII	Yes	No	nd

^aThe recombinant protein of the E2 expressed in E. coli was insoluble.